This application focuses on the development of a novel bacterial therapeutics targeting bacterial vaginosis (BV)-associated biofilm for the prevention and treatment of recurrent BV using a novel strain of Lactobacillus jensenii with a disrupted pox1 gene in the chromosome that exhibits highly potent activity against a Gardnerella vaginalis strain (ATCC 14018). As an important step to pursue this biofilm intervention strategy, we propose to further evaluate in vitro efficacy of this novel strain to inhibit clinical vaginal isolates of G. vaginalis and Atopobium vaginae in a co-culture model, and ability to prevent the development of Gardnerella- specific biofilm. BV is the most common infection of the reproductive tract among women of childbearing age globally. Control of BV recurrence has emerged as a global issue of concern, in light of its significant prevalence and pathophysiology among women of childbearing age. Epidemiologically, this disruption in vaginal ecology can lead to a serious disease burden of adverse obstetric and gynecologic outcomes, including adverse pregnancy outcomes and pelvic inflammatory disease. BV resembles a sexually transmitted disease (STD) and is positively associated with the acquisition of other STD. Moreover, BV is prominent in regions of the world associated with high HIV transmission rates and enhances viral replication and genital tract shedding of the HIV-1 and HSV-2 viruses, thereby further promoting the spread of STD. BV is a complex polymicrobial syndrome resulting from the depletion of the normal H2O2-producing lactobacilli in the vagina, overgrowth of BV-associated microorganisms, and the establishment of an adherent Gardnerella/Atopobium-specific biofilm. There are no long-term therapies for curing and preventing this frequently recurring BV condition. The recommended antibiotic treatments, the mainstay of current therapy, fail to eradicate biofilm that is an important predisposing factor for BV recurrence. There is an urgent need to develop innovative therapeutic approaches to target BV-associated biofilm. Successful completion of the proposed studies would position us to pursue potential clinical investigations to evaluate biofilm intervention strategies using bioengineered vaginal Lactobacillus. In combination with current antibiotic regimen, this product concept may have a great potential to shift current research or clinical practice paradigms for an effective treatment and prevention of recurrent BV globally. It would decrease the economical burden from repetitive treatments and potential adverse obstetric and gynecologic outcomes, while re-establishing a Lactobacillus-dominant healthy vaginal flora. PUBLIC HEALTH RELEVANCE: